The present invention relates to an endoscope connecting apparatus which transmits an object image.
Recently, a method has been used whereby, by attaching a television camera to an endoscope eyepiece optical system, a plurality of observers observe the same picture image using a monitor television. The picture image is recorded and repeatedly reproduced by a video system so that a highly precise diagnosis can be made.
In an endoscope, such as a blood vessel endoscope used during an operation, the above mentioned method has been used. However, this endoscope has a distinct clean area and an unclean area while using the endoscope during an operation. Generally, since a tool, such as a television camera, has a structure which cannot be disinfected and sterilized, the tool becomes an unclean area and an eyepiece part, being connected with the television camera, becomes an unclean area so that an operator cannot touch the eyepiece part. Thus, as shown in the Gazette of Japanese Patent Laid Open No. 232311/1984, an endoscope in which only an eyepiece part is separated from an operating part, which is frequently touched by an operator, is devised.
In order to make an endoscope simpler, smaller and lighter, in the Gazettes of Japanese Patent Laid Open No. 201134/1987 and Japanese Patent Laid Open No. 278016/1988, an eyepiece lens is removed from an endoscope and an image guide is directly connected to a television camera so as to form an object image. In U.S. Pat. No. 4,624,243, an endoscope in which an eyepiece and an inserting part can be removed is shown.
When an image guide is connected to a television camera or an eyepiece part, an image transmitted by the image guide enters a receiving light surface of the solid state imaging device or an eyepiece optical system. It is, therefore, necessary to make the optical axis on the side of the image guide correspond to the optical axis a) on the television camera or b) on the side of the eyepiece part so as to avoid losing a part of a border of the image.
Unless the end surface of the image guide is located on a focal position of a forming image lens system on an observing side, an object image which is in focus cannot be obtained. Therefore, it is necessary to make the distance between the television camera and the image guide always be equal to the distance between the side of the eyepiece part and the image guide.
In the above mentioned prior art of the Gazette of Japanese Patent Laid Open No. 278016/1988, this point however is not stated. In the Gazette of Japanese Patent Laid Open No. 201134/1987, a connector is removably held and fixed by a click mechanism. However, a positive means for making the optical axes and distances equal is not provided.
In U.S. Pat. No. 4,624,243, because an eyepiece is screwed into an inserting part, or vice versa, there is a problem that an optical axis of an image guide is not positioned on an optical axis of a forming image optical system due to misalignment between the screwed parts.
Furthermore, because of the misalignment of the screwed parts, it is impossible to focus the eyepiece so that a focusing mechanism must be provided in the forming image lens system and the focus needs to be adjusted by an operator for each operation, therefore, the operation of the device is complicated.